Statement–Assumption — Notice: “Private property — trespassers will be prosecuted.” Assumptions: I. Passers-by may read the notice and refrain from trespassing. II. People are deterred by the prospect of prosecution.

Introduction / Context:
A warning sign is a preventive tool. We evaluate which assumptions must hold for such signage to serve its purpose.

Given Data / Assumptions:

• The notice communicates ownership and legal consequences of unlawful entry.
• Signs work only if people can perceive (read/understand) them and are motivated to comply.

Concept / Approach:
The sign’s effectiveness relies on two premises: (a) that potential intruders will see and process the message (I), and (b) that the threat of legal action creates sufficient deterrence (II). If either premise fails, the sign loses much of its preventive value.

Step-by-Step Solution:
1) I is implicit: posting a notice presumes it will be read and will influence behavior.2) II is implicit: specifying prosecution aims to instill fear of legal penalties as a deterrent.

Verification / Alternative check:
Security best practices combine signaling (signs) and enforcement (guards/cameras); signaling presupposes perception and deterrence.

Why Other Options Are Wrong:
Selecting only one omits the dual foundation of signage (communication + deterrent value); “neither” denies the point of posting the notice.

Common Pitfalls:
Assuming that signs alone ensure compliance without recognizing the assumed psychological effect.

Final Answer:
if both I and II is implicit.